Stereoscopic image display apparatuses of the time-division shutter scheme, as it is called, are widely spread in various fields including medical treatment and amusement. The stereoscopic image display apparatus displays images by alternately switching between images for the right eye and images for the left eye. A user can watch stereoscopic images by using a shutter eyewear and watching images of the stereoscopic image display apparatus. Here, “shutter eyewear” refers to an eyewear having a shielding mechanism (hereinafter “shutters”) for alternately shielding the views of the left and right eyes in synchronization with switching of image display.
However, it takes a certain period of time to switch the open/closed state of the shutters (hereinafter “shutter switching”). In a period in which switching between the shutters is started and is finished (hereinafter “period of shutter switching”), light is allowed to be incident on both eyes. In this period of shutter switching, if the right-eye image is displayed, the right-eye image also enters the left eye, and, if the left-eye image is displayed, the left-eye image also enters the right eye. That is, the cross-talk between the right-eye image and the left-eye image occurs, and therefore it is not possible to display quality stereoscopic images.
Then, for example, Patent Literature 1 discloses a technique of preventing cross-talk between right-eye images and left-eye images.
FIG. 1 is an operation timing chart of a stereoscopic image display apparatus disclosed in Patent Literature 1. FIG. 1A shows the start timing and the end timing of a light emitting operation (hereinafter simply “light emission”) based on display data of each display line. FIG. 1B shows the open/closed state of a right-eye shutter at each timing. FIG. 1C shows the open/closed state of a left-eye shutter at each timing.
The panel of the stereoscopic image display apparatus is formed with, for example, 1080 display lines aligned in the vertical direction and in parallel to each other. Each display line is formed with, for example, a plurality of pixels aligned linearly in the horizontal direction. As shown in FIG. 1A, the stereoscopic image display apparatus sequentially performs write-scanning per display line of display data. Then, the stereoscopic image display apparatus starts light emission from each display line immediately after display data is written in each display line, and stops light emission from each display line after a certain period of time passes.
At first time t1 when light emission from all display lines is stopped completely, the stereoscopic image display apparatus outputs, to the shutter eyewear, a control signal for commanding to switch the right-eye shutter from the transmitting state to the shielding state, and switches the left-eye shutter from the shielding state to the transmitting state. At second time t2 when switching between the shutters of the shutter eyewear is finished, the stereoscopic image display apparatus starts write-scanning display data of the next left-eye image and emitting light. Hence, in period Sc of shutter switching between first time t1 and second time t2, images are not displayed.
Then, at third time t3 when light emission from all display lines is stopped completely, the stereoscopic image display apparatus outputs a control signal for commanding to switch the left-eye shutter from the transmitting state to the shielding state, and switch the right-eye shutter from the shielding state to the transmitting state. Then, at fourth time t4 after period Sc of shutter switching, the stereoscopic image display apparatus starts write-scanning display data of a right-eye image and emitting light.
According to this operation, it is possible to provide periods of light emission for right-eye images, periods of light emission for left-eye images and periods Sc of shutter switching not to overlap in the time domain, and prevent cross-talk between the right-eye images and the left-eye images.